Question: What island nation  has highest marriage age ?
Paraphrase: which island nation had the highest age of marriage?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q112099 . ?ent wdt:P3000 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: Singapore, Tuvalu, Samoa, Vanuatu, Papua New Guinea